Gerenciamento de resíduos de espécies tropicais da indústria madeireira da Amazônia Mato-grossense para fins energéticos

Abstract

This study aimed to analyze the management of residues generated by wood industries in the Mato Grosso Amazon and determine their properties to assess energy application viability. Information on management and collection residue samples encompassed 24 wood industries affiliated to the state unions, integrated into the Centro das Indústrias Produtoras e Exportadoras de Mato Grosso – CIPEM, distributed in 8 state municipalities. The first chapter assesses the management of residues/product and properties of granulometry, moisture, bulk density, ashes, and calorific value of particulate residues such as sawdust, shavings, and chips, in addition to a proposal of classification for these residues. The results for management demonstrate unequal residue proportions, predominantly with residues of sawdust and large chunks sold as firewood or destined for chip production. The commercial demand of sawdust is sufficient to vacate the industrial yard. 90% of the residues are used for energy purposes and have low content of ashes in general. Regarding the use of particulate residues/product, chips and sawdust have higher bulk densities, but also higher moisture content, therefore, measures should be applied to control the effect of moisture that reduces the available calorific value, compromising its use, especially in direct burning. The second chapter determines the properties of the residue sold as firewood of the 17 main Amazonian tropical species. For the basic density of residues, the species were differentiated into light wood species with a minimum density of 0.40 g.cm-3, moderate wood 0.67 g.cm-3, and high density with a maximum value of 0.95 g.cm-3. We found C levels above 49%, H close to 6%, and low atomic ratio for H/C, N/C, and O/C. Lignin was above 30%, while extractives varied between 3.3 and 23.6%. The levels of volatile matter were higher than 77%, 1.8% for ashes, and mean PCS was 20 MJ. kg-1 . The multivariate analysis showed the firewood of Aspidosperma spp., Mezilaurus itauba, Hymenolobium spp., Handroanthus spp., Ocotea spp., and especially Dipterix odorata with higher energy potential. We conclude that the particulate and firewood residues showed satisfactory properties for energy applications through combustion. For an improved efficiency of the combustion systems and considering the different combustion phases, we recommend the grouping of species with similar properties, as well as controlled combustion system supply.